/* proto_help.c
 * Routines for dynamic protocol help menus
 *
 * $Id$
 *
 * Edgar Gladkich <edgar.gladkich@incacon.de>
 * Gerald Combs <gerald@wireshark.org>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <string.h>

#include <gtk/gtk.h>
#include <gtk/webbrowser.h>

#include "../file.h"

#include <epan/prefs.h>
#include <epan/filesystem.h>
#include <epan/strutil.h>
#include <epan/proto.h>

#if GLIB_CHECK_VERSION(2,14,0) /* GRegex */

#define PH_MENU_TOP "/Protocol Help"

#define PH_FILE_LOG "ph.log"
#define PH_INI_SUFFIX ".ini"
#define PH_PATH_SEARCH_STR "${PATH}"

/* .ini Section names */
#define PH_INI_GROUP_DATABASE "database"
#define PH_INI_GROUP_LOCATION_DATA "location data"
#define PH_INI_GROUP_MAP "map"

/* .ini [database] section keys */
#define PH_INI_DB_KEY_SOURCE "source"
#define PH_INI_DB_KEY_LOCATION_TEMPLATE "location"

/* .ini Path sections */
#define PH_INI_KEY_OVERVIEW "_OVERVIEW"

/* Where to look for .ini files */
#define PH_CONFFILE_SUBDIR "protocol_help"

#ifdef PH_DEBUG_LOG
const gchar *ph_log_path;
#endif

typedef struct proto_help_key_file_t {
	GKeyFile *keyfile;
	const gchar *source;
	const gchar *loc_template;
} proto_help_key_file;

GPtrArray *g_ph_key_files = NULL;

GtkItemFactory *g_ph_menu_factory;

static void ph_menu_reset(void);
static void ph_menu_onclick(GtkWidget*, gpointer, guint);

static int ph_capture_get_protocol_id(GtkTreeSelection*, capture_file*);
static const gchar* ph_capture_get_protocol_name(GtkTreeSelection*, capture_file*);
static const gchar* ph_capture_get_protocol_abbrev(GtkTreeSelection*, capture_file*);
static gchar* ph_capture_get_description(capture_file*);

static proto_help_key_file *ph_ini_load_file(const gchar*);
static gchar* ph_ini_get_value(GKeyFile *, const gchar*, const gchar*, gchar *);
static gchar* ph_ini_get_path(GKeyFile *, const gchar*, const gchar*);
static gchar** ph_ini_get_keywords(GKeyFile *, const gchar*);

static guint ph_parse_string(const gchar*, const gchar*);

/* #define PH_DEBUG_LOG 1 */
#ifdef PH_DEBUG_LOG
static void ph_logging_handler(const gchar*, GLogLevelFlags, const gchar*, gpointer);
#endif

/** @file
 * Protocol help routines. Adds web browser links to protocol menu items
 * via configuration files.
 */

/** Initialization
 *
 * @param void
 * @return void
 */
#define PH_CONF_DIRS 2
void proto_help_init(void)
{
	gchar *search_dir[PH_CONF_DIRS];
	const gchar *ini_name;
	gchar *ini_path;
	GDir *conf_dir;
	proto_help_key_file *phkf;
	int i;

	search_dir[0] = g_strdup_printf("%s" G_DIR_SEPARATOR_S PH_CONFFILE_SUBDIR, get_datafile_dir());
	/* XXX - Use profiles? */
	search_dir[1] = get_persconffile_path(PH_CONFFILE_SUBDIR, FALSE, FALSE);

#ifdef PH_DEBUG_LOG
	g_log_set_handler(NULL, G_LOG_LEVEL_MASK | G_LOG_FLAG_FATAL | G_LOG_FLAG_RECURSION, ph_logging_handler, NULL);
#endif

	if (g_ph_key_files)
		return;

	g_ph_key_files = g_ptr_array_new();

	/* Start loop */

#ifdef PH_DEBUG_LOG
	ph_log_path = g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s", g_get_tmp_dir(), PH_FILE_LOG);
#endif

	for (i = 0; i < PH_CONF_DIRS; i++) {
		g_log(NULL, G_LOG_LEVEL_INFO, "Looking for protocol help files in '%s'", search_dir[i]);
		conf_dir = g_dir_open(search_dir[i], 0, NULL);
		if (!conf_dir) {
			continue;
		}

		while ((ini_name = g_dir_read_name(conf_dir)) != NULL) {
			if (! g_str_has_suffix(ini_name, PH_INI_SUFFIX)) {
				continue;
			}
			g_log(NULL, G_LOG_LEVEL_INFO, "-- Found '%s'", ini_name);
			ini_path = g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s", search_dir[i], ini_name);
			phkf = ph_ini_load_file(ini_path);
			g_free(ini_path);
		}
		g_dir_close(conf_dir);
	}
}

/** Initialize the menu
 *
 * @param widget Context menu root
 * @return void
 */
void proto_help_menu_init(GtkWidget *widget)
{
	g_ph_menu_factory = gtk_item_factory_from_widget(widget);
	ph_menu_reset();
}

/** Clear the menu
 *
 * @param void
 * @return void
 */
static void ph_menu_reset(void)
{
	GtkWidget *menu_item = NULL;
	GList *menu_entries = NULL;
	GList *menu_entry = NULL;

	if(!g_ph_menu_factory) return;

	menu_item = gtk_item_factory_get_widget(g_ph_menu_factory, PH_MENU_TOP);
	menu_entries = gtk_container_get_children(GTK_CONTAINER(menu_item));

	for(menu_entry = g_list_first(menu_entries); menu_entry != NULL; menu_entry = g_list_next(menu_entry))
	{
		gtk_container_remove(GTK_CONTAINER(menu_item), menu_entry->data);
	}

	menu_item = gtk_item_factory_get_item(g_ph_menu_factory, PH_MENU_TOP);
	gtk_widget_set_sensitive(menu_item, FALSE);
}

/* Callback to free URLs */
static void
url_destroy_cb(GtkWidget *w _U_, gpointer url) {
	g_free(url);
}

/** Fill in the protocol help menu
 *
 * @param selection Currently-selected packet
 * @param cf Capture file
 * @return void
 */
void proto_help_menu_modify(GtkTreeSelection *selection, capture_file *cf)
{
	gchar *description;
	const gchar *proto_abbrev, *proto_name;
	gchar *value;
	gchar **keys;
	GHashTable *table;
	guint i = 0, cur_kf;
	GtkWidget *menu_item = NULL;
	GtkItemFactoryEntry *menu_entry = NULL;
	proto_help_key_file* phkf;
	gchar *loc;
	gboolean add_separator = FALSE;
	gboolean found = FALSE;

	if(!g_ph_menu_factory) return;
	ph_menu_reset();

	proto_abbrev = ph_capture_get_protocol_abbrev(selection, cf);
	if(!proto_abbrev) return;

	proto_name = ph_capture_get_protocol_name(selection, cf);
	if(!proto_name) return;

	description = ph_capture_get_description(cf);

	for (cur_kf = 0; cur_kf < g_ph_key_files->len; cur_kf++) {
		phkf = (proto_help_key_file *) g_ptr_array_index(g_ph_key_files, cur_kf);
		g_assert(phkf);

		value = ph_ini_get_path(phkf->keyfile, proto_abbrev, PH_INI_KEY_OVERVIEW);

		if(!value)
		{
			g_log(NULL, G_LOG_LEVEL_DEBUG, "Overview page of the protocol '%s' is not defined", proto_abbrev);
			continue;
		}

		/*
		 * XXX - We could save some memory here if we stored the location template
		 * and search value as separate items. However, that makes freeing them
		 * a bit messy.
		 */
		loc = string_replace(phkf->loc_template, PH_PATH_SEARCH_STR, value);
		g_free(value);
		if (!loc || !strlen(loc)) continue;

		if (add_separator) {
			menu_entry = g_malloc0(sizeof(GtkItemFactoryEntry));
			menu_entry->path = g_strdup_printf("%s/<separator>", PH_MENU_TOP);
			menu_entry->item_type = "<Separator>";
			gtk_item_factory_create_item(g_ph_menu_factory, menu_entry, NULL, 2);
		}
		add_separator = TRUE;

		menu_entry = g_malloc0(sizeof(GtkItemFactoryEntry));
		menu_entry->path = g_strdup_printf("%s/%s %s Overview", PH_MENU_TOP, phkf->source, proto_name);
		menu_entry->callback = ph_menu_onclick;
		gtk_item_factory_create_item(g_ph_menu_factory, menu_entry, loc, 2);
		menu_item = gtk_item_factory_get_widget(g_ph_menu_factory, menu_entry->path);
		g_assert(menu_item);
		g_signal_connect(menu_item, "destroy", G_CALLBACK(url_destroy_cb), loc);

		found = TRUE;

		if(description)
		{
			keys = ph_ini_get_keywords(phkf->keyfile, proto_abbrev);
			table = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);

			for(i = 0; keys[i] != NULL; i++)
			{
				if(!strcmp(keys[i], PH_INI_KEY_OVERVIEW)) continue; /* We already added the overview */
				if(!ph_parse_string(description, keys[i])) continue; /* Bad format */
				if(g_hash_table_lookup(table, g_ascii_strup(keys[i], -1)) != NULL) continue; /* Duplicate */

				value = ph_ini_get_path(phkf->keyfile, proto_abbrev, keys[i]);
				if(!value || !strlen(value)) continue;

				loc = string_replace(phkf->loc_template, PH_PATH_SEARCH_STR, value);
				g_free(value);
				if (!loc || !strlen(loc)) continue;

				g_hash_table_insert(table, g_ascii_strup(keys[i], -1), GINT_TO_POINTER(1));

				menu_entry = g_malloc0(sizeof(GtkItemFactoryEntry));
				menu_entry->path = g_strdup_printf("%s/%s", PH_MENU_TOP, keys[i]);
				menu_entry->callback = ph_menu_onclick;
				gtk_item_factory_create_item(g_ph_menu_factory, menu_entry, loc, 2);
				menu_item = gtk_item_factory_get_widget(g_ph_menu_factory, menu_entry->path);
				g_assert(menu_item);
				g_signal_connect(menu_item, "destroy", G_CALLBACK(url_destroy_cb), loc);
			}

			g_hash_table_destroy(table);
		}
	}

	g_free(description);
	menu_item = gtk_item_factory_get_item(g_ph_menu_factory, PH_MENU_TOP);
	gtk_widget_set_sensitive(menu_item, found);
}

/**
* Function ph_menu_onclick
*
* @param GtkWidget *widget Description
* @param gpointer data Description
* @param guint action Description
* @return void
*/
static void ph_menu_onclick(GtkWidget *widget _U_, gpointer data, guint action _U_)
{
	gchar *loc = (gchar *) data;

	g_log(NULL, G_LOG_LEVEL_DEBUG, "Sending '%s' to the browser.", loc);

	if (! loc) {
		g_log(NULL, G_LOG_LEVEL_DEBUG, "Protocol help ended up with a NULL URL.");
		return;
	}

	/* XXX - Should we do any RFC 3986 escaping first? */
	if (! browser_open_url(loc)) {
		g_log(NULL, G_LOG_LEVEL_DEBUG, "Couldn't get protocol help for %s", loc);
	}
}

/** Get the field ID for a selected tree item.
 *
 * @param selection Tree selection
 * @param cfile Capture file
 * @return Field ID or 0
 */
static int
ph_capture_get_protocol_id(GtkTreeSelection *selection, capture_file *cf)
{
	GtkTreeModel *model = NULL;
	GtkTreeIter iter;
	GtkTreeIter parent;
	field_info *finfo = NULL;
	int proto_id = 0;

	if(!cf->finfo_selected) return 0;
	proto_id = cf->finfo_selected->hfinfo->id;

	if(!proto_id)
	{
		if(!gtk_tree_selection_get_selected(GTK_TREE_SELECTION(selection), &model, &iter)) return 0;

		while(gtk_tree_model_iter_parent(model, &parent, &iter))
		{
			gtk_tree_model_get(model, &parent, 1, &finfo, -1);
			iter = parent;

			if(finfo->hfinfo->id > 0)
			{
				proto_id = finfo->hfinfo->id;
				break;
			}
		}
	}

	while(proto_id && !proto_registrar_is_protocol(proto_id))
	{
		proto_id = proto_registrar_get_parent(proto_id);
	}

	return proto_id;
}

/** Get the protocol name for a selected tree item.
 *
 * @param selection Tree selection
 * @param cfile Capture file
 * @return Name for a protocol or NULL
 */
static const gchar*
ph_capture_get_protocol_name(GtkTreeSelection *selection, capture_file *cf)
{
	int proto_id = ph_capture_get_protocol_id(selection, cf);

	return (!proto_id) ? NULL : proto_get_protocol_short_name(find_protocol_by_id(proto_id));
}

/** Get the abbreviated protocol name for a selected tree item.
 *
 * @param selection Tree selection
 * @param cfile Capture file
 * @return Abbreviated (lower-case) name for a protocol or NULL
 */
static const gchar*
ph_capture_get_protocol_abbrev(GtkTreeSelection *selection, capture_file *cf)
{
	int proto_id = ph_capture_get_protocol_id(selection, cf);

	return (!proto_id) ? NULL : proto_registrar_get_abbrev(proto_id);
}

/** Return the selected item description
 * @param cf capture file pointer
 * @return Description of the selected item. MUST be freed with g_free().
 */
static gchar* ph_capture_get_description(capture_file *cf)
{
	gchar *buffer = NULL;

	if(cf->finfo_selected->rep->representation != 0)
	{
		buffer = g_strdup(cf->finfo_selected->rep->representation);
	}
	else
	{
		buffer = g_malloc(ITEM_LABEL_LENGTH);
		proto_item_fill_label(cf->finfo_selected, buffer);
	}

	return buffer;
}

/** Load a protocol help key file and add it to the global array.
 *
 * @param filename Full path to the key file.
 * @return Newly-created key file entry or NULL.
 */
static proto_help_key_file *
ph_ini_load_file(const gchar *filename)
{
	GKeyFile *kf;
	GError *error = NULL;
	proto_help_key_file *phkf = NULL;
	gchar *old_template, *loc_template;
	gchar **loc_data, *loc_repl, *loc_search;
	gsize i, len;

	if(!g_file_test(filename, G_FILE_TEST_EXISTS))
	{
		g_log(NULL, G_LOG_LEVEL_DEBUG, "Configuration file %s does not exists", filename);
		return NULL;
	}

	kf = g_key_file_new();

	if(!g_key_file_load_from_file(kf, filename, G_KEY_FILE_NONE, &error))
	{
		g_log(NULL, G_LOG_LEVEL_DEBUG, "Configuration file '%s' could not be loaded (%s)", filename, error->message);
		g_error_free(error);
		g_key_file_free(kf);

		return NULL;
	}

	loc_template = ph_ini_get_value(kf, PH_INI_GROUP_DATABASE, PH_INI_DB_KEY_LOCATION_TEMPLATE, NULL);
	if (!loc_template) {
		g_key_file_free(kf);
		return NULL;
	}

	loc_data = g_key_file_get_keys(kf, PH_INI_GROUP_LOCATION_DATA, &len, NULL);
	if (loc_data) {
		for (i = 0; i < len; i++) {
			loc_repl = ph_ini_get_value(kf, PH_INI_GROUP_LOCATION_DATA, loc_data[i], NULL);
			old_template = loc_template;
			loc_search = g_strdup_printf("${%s}", loc_data[i]);
			loc_template = string_replace(loc_template, loc_search, loc_repl);
			g_free(loc_repl);
			g_free(loc_search);
			g_free(old_template);
		}
	}

	/* Add ${PATH} to the end if it's not present */
	if (!strstr(loc_template, PH_PATH_SEARCH_STR)) {
		old_template = loc_template;
		loc_template = g_strdup_printf("%s" PH_PATH_SEARCH_STR, old_template);
		g_free(old_template);
	}

	phkf = g_malloc(sizeof(proto_help_key_file));
	phkf->keyfile = kf;
	phkf->source = ph_ini_get_value(kf, PH_INI_GROUP_DATABASE, PH_INI_DB_KEY_SOURCE, "(Unknown source)");
	phkf->loc_template = loc_template;

	g_ptr_array_add(g_ph_key_files, phkf);

	return phkf;
}

/** Fetch a value for a key from a key file with an optional default value.
 *
 * @param keyfile The key file to search
 * @param group Key file group
 * @param key Key file value to fetch
 * @param alt Alternate string to return. May be NULL.
 * @return const gchar* A newly-allocated key value, or a copy of alt if not found.
 */
static gchar*
ph_ini_get_value(GKeyFile *keyfile, const gchar *group, const gchar *key, gchar *alt)
{
	gchar *value = NULL;

	if (keyfile) {
		value = g_key_file_get_string(keyfile, group, key, NULL);
	}

	if (!value) {
		value = g_strdup(alt);
	}

	return value;
}

/** Given a protocol name and a key, map the protocol name to a section in the
 * keyfile, then look up the value for that key.
 *
 * @param keyfile The key file to search
 * @param protocol Wireshark protocol name to map, e.g. "tcp".
 * @param keyword The key to fetch from the mapped section.
 * @return
 */
static gchar*
ph_ini_get_path(GKeyFile *keyfile, const gchar *protocol, const gchar *keyword)
{
	GError *error = NULL;
	gchar *map;
	gchar *value;

	if(!keyfile || !protocol || !keyword) return NULL;

	map = g_key_file_get_string(keyfile, PH_INI_GROUP_MAP, protocol, &error);

	if(!map)
	{
		g_log(NULL, G_LOG_LEVEL_DEBUG, "Protocol '%s' is not defined (%s)", protocol, error->message);
		g_error_free(error);
		return NULL;
	}

	value = g_key_file_get_string(keyfile, map, keyword, NULL);
	g_free(map);
	return value;
}

/** Given a protocol name, map it to a section in the keyfile, then
 * return the keys in that section.
 *
 * @param keyfile The key file to search
 * @param protocol Wireshark protocol name to map, e.g. "tcp".
 * @return An array of keys in the mapped section. Must be freed with g_strfreev().
 */
static gchar**
ph_ini_get_keywords(GKeyFile *keyfile, const gchar *protocol)
{
	GError *error = NULL;
	gchar *map;
	gchar **keys;
	gsize length = 0;

	if(!keyfile) return NULL;

	map = g_key_file_get_string(keyfile, PH_INI_GROUP_MAP, protocol, &error);

	if(!map)
	{
		g_log(NULL, G_LOG_LEVEL_DEBUG, "Protocol '%s' is not defined (%s)", protocol, error->message);
		g_error_free(error);
		return NULL;
	}

	error = NULL;
	keys = g_key_file_get_keys(keyfile, map, &length, &error);
	g_free(map);

	if(!keys)
	{
		g_log(NULL, G_LOG_LEVEL_DEBUG, "Display titles are not defined (%s)", protocol);
		g_error_free(error);
	}

	return keys;
}

/**
* Function ph_parse_string
*
* @param const gchar *description Description
* @param const gchar *value Description
* @return guint Description
*/
static guint ph_parse_string(const gchar *description, const gchar *value)
{
	GRegex *regex = NULL;
	GMatchInfo *match_info = NULL;
	gchar *pattern = NULL;
	guint result = 0;

	pattern = g_strdup_printf("(?<![0-9a-zA-Z_])%s(?![0-9a-zA-Z_])", value);
	regex = g_regex_new(pattern, 0, 0, NULL);

	g_regex_match(regex, description, 0, &match_info);
	if(g_match_info_matches(match_info)) result = 1;

	g_match_info_free(match_info);
	g_regex_unref(regex);

	return result;
}

#ifdef PH_DEBUG_LOG
/**
 * Function ph_logging_handler
 *
 * @param const gchar *domain Description
 * @param GLogLevelFlags level Description
 * @param const gchar *message Description
 * @param gpointer data Description
 * @return void
 */
static void ph_logging_handler(const gchar *domain _U_, GLogLevelFlags level, const gchar *message, gpointer data _U_)
{
	gchar *log = NULL;
	gchar *type = NULL;
	FILE *file = NULL;
	struct tm *timestamp = NULL;
	time_t now;

	time(&now);
	timestamp = localtime(&now);

	switch(level & G_LOG_LEVEL_MASK)
	{
		case G_LOG_LEVEL_ERROR:
			type = "ERR";
			break;

		case G_LOG_LEVEL_DEBUG:
			type = "WARNING";
			break;

		case G_LOG_LEVEL_INFO:
			type = "INFO";
			break;

		default:
			type = "OTHER";
	}

	file = ws_fopen(ph_log_path, "a+");

	if(file)
	{
		log = g_strdup_printf("[%04u-%02u-%02u %02u:%02u:%02u %s] %s\n", timestamp->tm_year + 1900, timestamp->tm_mon + 1, timestamp->tm_mday, timestamp->tm_hour, timestamp->tm_min, timestamp->tm_sec, type, message);
		fputs(log, file);
		fclose(file);
	}
}
#endif /* PH_DEBUG_LOG */

#else /* GLIB_CHECK_VERSION(2,14,0) */ /* No GRegex */

void proto_help_init(void) {}
void proto_help_menu_init(GtkWidget *widget _U_) {}
void proto_help_menu_modify(GtkTreeSelection *selection _U_, capture_file *cf _U_) {}

#endif /* GLIB_CHECK_VERSION(2,14,0) */